The 30-share index started the day on a firm footing at 19,970.02, higher by 118 points from yesterday's close. It, however, erased some of the early gains during the day and closed 97.50 points, or 0.49 per cent higher at 19,948.73. Sensex had closed down by 183.25 points in the previous session. The Nifty closed at 5,973.25, up 18.05 points or 0.30 per cent. It touched a high of 5,989.80 and a low of 5,926.75 in trade today.